Strainer device



E. A. OWEN STRAINER DEVICE June 22, 1937.

Filed July 13, 1935 R O T N E V m EUGENEA. UWEN BY ATTORNEY Patented June 22, 1937 UNITED STATES ATENT OFFICE STRAINER DEVICE Application July 13,

8 Claims.

This invention relates to a combined air strainer and intake silencer adapted for use in the intake passage of an air compressor.

It is the principal object of this invention to provide a combined air strainer and intake silencer adapted to be interposed in the intake passage of an air compressor and which will operate to remove impurities from the air which flows therethrough and to reduce or eliminate noise as a result of the flow of air to the compressor.

It is a further object of this invention to provide an air strainer having a straining unit which can be readily removed and replaced when desired for cleaning or for other purposes.

It is another object of this invention to provide an air strainer adapted to be interposed in the passage leading to a compressor intake valve and having provision for connecting a conduit leading from the crank case of the compressor to the passage leading to the compressor intake valve at a point intermediate the valve and the strainer unit.

A further object of the invention is to provide an air strainer having chambers therein through which the air flows and which are provided with yieldable walls which flex in response to pulsations in the flow of air through the strainer, and thereby reduce or eliminate noise occasioned by the flow of air to the compressor.

A. further object of the invention is to provide an improved air strainer and intake silencer.

Other objects of the invention and features of novelty will be apparent from the following description taken in connection with the accompanying drawing, in which I Fig. 1 is a view largely in section of a compressor equipped with the combined air strainer and intake silencer provided by my invention;

40 Fig. 2 is a sectional view of the strainer, this View being taken substantially along the line 2-2 of Fig. 1; and

Fig. 3 is a sectional View taken substantially along the line 3--3 of Fig. 1.

Referring to the drawing I have illustrated one 4 form of the improved air strainer device provided by my invention as applied to a single cylinder compressor. As shown, there is a compressor comprising a body having a substantially closed 50 crank case chamber 2 formed therein, and hav-- ing a cylinder 3 secured thereto by suitable means. The cylinder 3 has a bore therein in which is positioned a piston 4, while the upper end of the bore in the cylinder 3 is closed by a 55; cylinder head 6 which is detachably secured to 1935, Serial No. 31,240

the cylinder 3, and which has a, chamber 8 formed therein in which is located the discharge valve 9 and which communicates with a reservoir, (not shown), by way of the pipe Ill. The cylinder head 6 also has a chamber l2 formed therein in which is positioned the inlet valve It, and which communicates with the atmosphere by way of the passage l5.

The improved air strainer and intake silencer provided by my invention comprises a body indicated generally by the reference numeral 20, and having a passage 2| extending therethrough, one end of the passage 2| being surrounded by a fiat mounting face 22 adapted to be secured against a similar mounting face 24 formed on the cylinder head 6 surrounding the passage IS. The body 28 is held in position against the mounting face '24 by means of cap screws 26 which extend through aligned apertures 21 in the walls of the body 2E3 and into threaded openings in the cylinder head 6.

The body 2!! has an inwardly projecting flange 28 formed adjacent the upper end thereof and this flange is adapted to be engaged by the peripheral portion of a diaphragm 30 which is shaped to fit the passage 2| through the body and which extends across this passage. The diaphragm 39 is substantially concavo-convex in cross-section and is provided with a pair of openings 3| through which air flows from one side of the diaphragm to the other. The diaphragm 3!) may be constructed of any suitable resilient material, such as molded rubber composition, and is arranged in the passage in the body 20 with the convex side towards the projecting shoulder 28.

A second diaphragm, indicated by the reference numeral 32 and similar in construction to the diaphragm 3|], is positioned in the passage through the body 20, being located adjacent the opposite end of this passage from the diaphragm 30, and having its peripheral portion in engagement with a securing member 35, which comprises a spring wire positioned in a groove 31 which extends around the interior of the member 26. This diaphragm has its concave face turned towards the other diaphragm.

A quantity of a suitable air straining material, such as curled hair, indicated by the reference numeral 40, is positioned in the passage 2| intermediate the diaphragms and 32 and is held in spaced relationship to these diaphragms by means of sections of screen or perforated metal 4| and 42 which engage the peripheral portions of the diaphragms 3|] and 32 and form chambers 43 and 44 intermediate the straining material and the diaphragms.

The quantity of curled hair placed in the strainer is sufiicient to more than fill the space between the screens 4| and 42 when the material is in its expanded condition. The curled hair is compressed somewhat when the diaphragm 32 is fitted in place and the hair, due to its inherent resiliency, tends to expand and to maintain the diaphragm in position against the shoulder 28 and the diaphragm 32 against the securing member 35.

A cover 45 is provided for the open end of the body 20, and as shown in the drawing, this cover comprises a member molded of a suitable composition, such as rubber, and having a rim portion 46 which is adapted to extend around and engage a bead 47 which surrounds the marginal portion of the housing 2B. The cover 45 is concavo-cohvex in cross-section, as is clearly shown in the drawing, so as to provide a chamber 48 between the diaphragm 32 and the cover 45.

The cover 45 is provided with a central opening 49 which communicates with the chamber 48 and with the atmosphere and the inner face of the cover 45 is provided with a plurality of radially extending ribs 50 which reinforce the wall of the cover adjacent the opening 49 and serve to maintain the cover at all times in spaced relationship relative to the diaphragm 32.

The body 20 has an extension on one side thereof and has an opening 55 through a wall of this portion of the body and which communicates with the passage 2! through the strainer at a point intermediate the compressor and the air straining means, and a pipe 58 is secured in this opening and communicates with the crank case chamber 2.

In operation, on the downward stroke of the piston 4 a partial vacuum or region of reduced pressure is created in the chamber in the cylinder above the piston 4 and this causes the intake valve M to open to permit air to flow through the air straining device into the cylinder.

On the opening of the inlet valve N there will be a reduction in the pressure of the fluid in the portion of the passage 2! intermediate the diaphragm 30 and the compressor, and fluid will thereupon flow from the chamber 43 through the openings 3i in the diaphragm 36, thus reducing the pressure of the fluid in the chamber 43. On a reduction in the pressure of the fluid in this chamber, fluid will flow from the chamber 44 to the chamber 43 through the curled hair or air straining material 40 and in passing through this material any dirt or foreign matter carried by the air will be removed.

A reduction in the pressure of fluid in the chamber 44 will cause air to flow to this chamber through the passages 33 in the diaphragm 32 from the chamber 48, which is in constant communication with the atmosphere by way of the passage 49.

When the piston 4 reaches the bottom of the stroke and starts its upward travel the intake valve [4 will close and the flow of air to the compressor through the air straining device will be out 01f and the pressure of the fluid in the various portions of the device will tend to equalize.

The diaphragms 30, 32 and 45 are constructed of resilient material and are adapted to yield or flex in response to variations in the pressure of the fluid on opposite sides thereof which result from pulsations in the flow of fluid through the strainer and these movements of the diaphragms tend to reduce or destroy noise produced by the air or fluid flowing to the compressor.

On the downward stroke of the piston 4, and the creation of a partial vacuum or region of reduced pressure in the portion of the air straining device intermediate the diaphragm 30 and the compressor, fluid will tend to flow to this portion of the device from the crank case chamber 2 by way of the pipe 58. This results in the creation of a slight vacuum in the crank case chamber 2, and this causes air to flow into the crank case chamber through the joints between the sections comprising the chamber and thus prevent the escape of lubricant from the crank case chamber.

A somewhat higher degree of vacuum or reduction in pressure will be effected in the portion of the air straining device intermediate the air straining material and the compressor than in other portions of the air straining device because of the resistance which the air straining material offers to the flow of air, and as the connection to the crank case chamber is efiected at this point, a somewhat higher vacuum of greater degree of reduction in pressure in the crank case chamber will be effected than if the connection to this chamber were made at some other point on the device, and because of the greater vacuum in the crank case chamber there will be less possibility of escape of lubricant therefrom.

The air straining device provided by this invention is constructed in such a manner that the air straining material may be removed and replaced. at any time without removing the device from the compressor. In order to remove the air straining material 40 the cover 45 is removed by stretching the rim 46 over the bead 41, while the diaphragm 32 is removed by removing the spring wire 35, whereupon the diaphragm 32 and the screen or perforated member 42 may both be removed through the opening in the lower end of the air straining device. The air cleaning material 40 may then be removed.

While one embodiment of the combined air strainer and intake silencer provided by my invention has been illustrated and described in detail it should be understood that the invention is not limited to these details of construction and that numerous changes and modifications may be made without departing from the scope of the following claims.

Having now described my invention, what I claim as new and desire to secure by Letters Patent, is:

1. In a device of the class described, a body having a passage therethrough through which fluid supplied to the intake valve of a compressor passes, airstraining means interposed in said passage, and a pair of diaphragms extending across said passage, one of said diaphragms being located on one side of the air straining means, the other of said diaphragms being located on the other side of the air straining means, each of said diaphragms having an opening formed therein through which fluid flows from one side of the diaphragm to the other, each of said diaphragms being adapted to yield in response to variations in the pressure of the fluid on opposite sides thereof.

2. In a device of the class described, a body having a passage therethrough through which fluid supplied to the intake valve of a compressor passes, air straining means interposed in said passage, a perforated member extending across said passage and confining the air straining means, and a substantially concavo-convex diaphragm extending across said passage, the concave side of the diaphragm being disposed toward the air straining'means, whereby a chamher is formed on the face of the air straining means, the diaphragm having an opening formed therein through which fluid flows from one side thereof to the other, said diaphragm being adapted to yield in response to variations in the pressure of the fluid on opposite sides thereof.

3. In a device of the class described, a body having a passage therethrough through which fluid supplied to the intake valve of a compressor passes, air straining means interposed in said passage, perforated members extending across said passage, one of said members being located on one side of the air straining means and the other of said members being located on the other side of the air straining means, said members being operable to maintain the air straining means in position in said passage, and a pair of concavo-convex diaphragms extending across said passage, one of said diaphragms disposed on one side of the air straining means, the other of the diaphragms being disposed on the other side of the air straining means, each of said diaphragms having its concave side disposed toward the air straining means and having an opening formed therein through which fluid flows from one side of the diaphragm to the other, each of the diaphragms being adapted to yield in re sponse to variations in the pressure of fluid on opposite sides thereof.

4,. In a device of the class described, a body having a passage therethrough through which fluid suppiied to the intake valve of a compressor passes, air straining means interposed in said passage, a pair of diaphragms extending across the passage and positioned on the side of the air straining means remote from the compressor, said diaphragms being maintained in spaced relationship whereby a chamber is formed therebetween, each of said diaphragms having an opening therein through which communication is established between the chamber and the opposite side of the diaphragm, one of said diaphragms having means disposed adjacent the midportion thereof to limit movement of said diaphragms towards each other.

5. In a device of the class described, a body having a passage therethrough through which fluid supplied to the intake valve of a compressor passes, air straining means interposed in said passage, a pair of diaphragms extending across said passage, one of said diaphragms being lo cated on one side of the air straining means, the other of said diaphragms being located on the other side of the air straining means, each of said diaphragms having an opening formed therein through which fluid flows from. one side of the diaphragm to the other, each of said diaphragms being adapted to yield in response to variations in the pressure of the fluid on opposite sides thereof, and means to detachably secure said diaphragms and said air straining means in position in said passage.

6. In a device of the class described, a body having a passage therethrough through which fluid supplied to the intake valve of a compressor passes, air straining means interposed in said passage, a pair of diaphragms extending across said passage, one of said diaphragms being located on one side of the air straining means, the other of said diaphragms being located on the other side of the air straining means, each of said diaphragms having an opening formed therein through which fluid flows from one side of the diaphragm to the other, each of said diaphragms being adapted to yield in response to variations in the pressure of the fluid on opposite sides thereof, the body having means projecting into the passage and adapted to be engaged by one of said diaphragms to prevent movement of said diaphragm in one direction in said passage, and means adapted to be detachably secured to said body and to be engaged by the other of said diaphragms to limit movement of said diaphragm in the opposite direction in said passage.

7. In a device of the class described, a body having a passage extending therethrough through which fluid supplied to the intake valve of a compressor passes, said body having means extending into said passage, a diaphragm extending across said passage and engaging the means extending thereinto whereby movement of said diaphragm in one direction is prevented, a second diaphragm extending across said passage, means adapted to be detachably secured to said body and to be engaged by said second diaphragm to limit movement of said diaphragm away from the first diaphragm more than a predetermined distance, and air straining means positioned between said diaphragms and adapted by its inherent resilience to maintain the diaphragms in engagement with the means limiting movement thereof.

8. In a device of the class described, a body having a passage extending therethrough through which fluid supplied to the intake valve of a compressor passes, air straining means interposed in said passage, a flexible diaphragm extending across said passage at a point intermediate the air straining means and the compressor inlet valve, said diaphragm having chambers on opposite sides thereof and having an opening therein through which air may flow between the chambers on the opposite sides thereof, a pair of flexible diaphragms extending across said passage on the side of the air straining means remote from the compressor inlet valve, the diaphragm adjacent the air straining means having chambers formed on the opposite sides thereof and having an opening therein through which fluid may flow between said chambers, the other of said diaphragms having an opening therein spaced from the opening in the diaphragm ad- Jacent the air straining means, and means carried by one of said diaphragms for limiting movement of the said diaphragms toward each other.

EUGENE A. OWEN. 

